Speech synthesis is a technique to convert any text containing sentences to synthesized speech. In order to realize speech quality of a user, a system creates a user-customized dictionary for speech synthesis by utilizing a large amount of user speech.
The system collects and records the user speech of all predefined number of texts before creating the user-customized dictionary. Therefore, it is unable to check quality of synthesized speech in the process of recording. It forces the user to continue to utter texts despite the quality of synthesized speech being high enough.